Thomas vaeney



UNITED STATES PATENT OFFICE.

THOMAS VARNEY, OF OAKLAND, CALIFORNIA.

PROCESS OF. DRYING N ITRATES.

SPECIFICATION formingpart of Letters Patent No. 249,275, dated November8, 1881.

i Application filed August 16, 1881. (No specimens.) 7

To all whom it may concern:

Be it known that I, THOMAS VARNEY, of Oakland, county of Alameda, andState of Galifornia,have invented a new and useful Process for DryingCertain Nitrates, of which the following is a specification.

The purpose of my invention is to dry various nitrates, and especiallythose of soda and potash, and at the same time prepare them for thegrinding-mill.

Niter is usually dried with heat so regulated as not to melt thecrystals. This requires great care as to the temperature, and muchlaborin stirring, and a great deal of time. By melting niter the wateris all expelled, even that of crystallization. It cools when undisturbedinto a solid amorphous cake, which grinds easily and finely. Theobjections to this mode are that it requires a large amount of heat andgreat labor in breaking the cake for the mill.

I have discovered that when ordinary nitercrystals are mixed in properproportion with molten niter the great heat of the latter (nearly 600Fahrenheit) rapidly and throughly expels the water from the crystals,and changes them, to a great extent, from the crystalline to theamorphous state, whereby they are pulverized much more readily andfinely than when crystalline, and as one part of molten niter willsuddenly dry from one to two parts of crystalline niter much heat andtime and labor are saved. All that is necessary is that the hot niter bewell mixed with the cold. In operating on a large scale themelting-kettle is set in brickwork, and has a discharge-pipe in thebottom closed with a valve. The kettle may be filled at once and fireapplied but I prefier to first put in a moderate quantity, enoughto'give a depth of about six (6) inches of the melted niter, and addmore from time to time, as the melting of crystalline niter convenientfor working isthen placed on a cement floor beneath the end of thedischarge-pipe. The valve is then opened, and a stream of molten niterruns upon an inclined iron plate, by which the stream is dispersed andshowered upon the undried niter, causing a hissing noise and the rapidemission of steam. The hot and cold niter are constantly and vigorouslystirred and mixed together with hoes or shovels, or otherwise, so as toprevent the formation of lumps and to distribute each kind of niterevenly. In a few minutes the entire mass becomes white and ceases togive off steam,when the hot niter is shut off and the mass is removedand a new batch treated.

The stirring can be done by machinery, if desired.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

The process of drying nitrates by melting a portion thereof andinixingit'with an unmelted portion, suhstan tiall y in the mannerdescribed.

THOMAS VARNEY.

Witnesses:

Ross SMALL, ALFRED RIX.

takes place, until the kettle is full. A quantity

